System and method providing arc welding training in a real-time simulated virtual reality environment using real-time weld puddle feedback

ABSTRACT

A real-time virtual reality welding system including a programmable processor-based subsystem, a spatial tracker operatively connected to the programmable processor-based subsystem, at least one mock welding tool capable of being spatially tracked by the spatial tracker, and at least one display device operatively connected to the programmable processor-based subsystem. The system is capable of simulating, in virtual reality space, a weld puddle having real-time molten metal fluidity and heat dissipation characteristics. The system is further capable of displaying the simulated weld puddle on the display device in real-time.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This patent application claims priority to and the benefit of U.S.Provisional Patent Application Ser. No. 61/090,794 filed on Aug. 21,2008, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

Certain embodiments relate to virtual reality simulation. Moreparticularly, certain embodiments relate to systems and methods forproviding arc welding training in a simulated virtual realityenvironment or augmented reality environment using real-time weld puddlefeedback.

BACKGROUND

Learning how to arc weld traditionally takes many hours of instruction,training, and practice. There are many different types of arc weldingand arc welding processes that can be learned. Typically, welding islearned by a student using a real welding system and performing weldingoperations on real metal pieces. Such real-world training can tie upscarce welding resources and use up limited welding materials. Recently,however, the idea of training using welding simulations has become morepopular. Some welding simulations are implemented via personal computersand/or on-line via the Internet. However, current known weldingsimulations tend to be limited in their training focus. For example,some welding simulations focus on training only for “muscle memory”,which simply trains a welding student how to hold and position a weldingtool. Other welding simulations focus on showing visual and audioeffects of the welding process, but only in a limited and oftenunrealistic manner which does not provide the student with the desiredfeedback that is highly representative of real world welding. It is thisactual feedback that directs the student to make necessary adjustmentsto make a good weld. Welding is learned by watching the arc and/orpuddle, not by muscle memory.

Further limitations and disadvantages of conventional, traditional, andproposed approaches will become apparent to one of skill in the art,through comparison of such approaches with embodiments of the presentinvention as set forth in the remainder of the present application withreference to the drawings.

SUMMARY

An arc welding simulation has been devised that provides simulation of aweld puddle in a virtual reality space having real-time molten metalfluidity characteristics and heat absorption and heat dissipationcharacteristics.

In an embodiment of the present invention, a virtual reality weldingsystem includes a programmable processor-based subsystem, a spatialtracker operatively connected to the programmable processor-basedsubsystem, at least one mock welding tool capable of being spatiallytracked by the spatial tracker, and at least one display deviceoperatively connected to the programmable processor-based subsystem. Thesystem is capable of simulating, in virtual reality space, a weld puddlehaving real-time molten metal fluidity and heat dissipationcharacteristics. The system is further capable of displaying thesimulated weld puddle on the display device to depict a real-world weld.Based upon the student performance, the system will display an evaluatedweld that will either an acceptable or show a weld with defects.

These and other features of the claimed invention, as well as details ofillustrated embodiments thereof, will be more fully understood from thefollowing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example embodiment of a system block diagram of asystem providing arc welding training in a real-time virtual realityenvironment;

FIG. 2 illustrates an example embodiment of a combined simulated weldingconsole and observer display device (ODD) of the system of FIG. 1;

FIG. 3 illustrates an example embodiment of the observer display device(ODD) of FIG. 2;

FIG. 4 illustrates an example embodiment of a front portion of thesimulated welding console of FIG. 2 showing a physical welding userinterface (WUI);

FIG. 5 illustrates an example embodiment of a mock welding tool (MWT) ofthe system of FIG. 1;

FIG. 6 illustrates an example embodiment of a table/stand (T/S) of thesystem of FIG. 1;

FIG. 7A illustrates an example embodiment of a pipe welding coupon (WC)of the system of FIG. 1;

FIG. 7B illustrates the pipe WC of FIG. 7A mounted in an arm of thetable/stand (TS) of FIG. 6;

FIG. 8 illustrates various elements of an example embodiment of thespatial tracker (ST) of FIG. 1;

FIG. 9A illustrates an example embodiment of a face-mounted displaydevice (FMDD) of the system of FIG. 1;

FIG. 9B is an illustration of how the FMDD of FIG. 9A is secured on thehead of a user;

FIG. 9C illustrates an example embodiment of the FMDD of FIG. 9A mountedwithin a welding helmet;

FIG. 10 illustrates an example embodiment of a subsystem block diagramof a programmable processor-based subsystem (PPS) of the system of FIG.1;

FIG. 11 illustrates an example embodiment of a block diagram of agraphics processing unit (GPU) of the PPS of FIG. 10;

FIG. 12 illustrates an example embodiment of a functional block diagramof the system of FIG. 1;

FIG. 13 is a flow chart of an embodiment of a method of training usingthe virtual reality training system of FIG. 1;

FIGS. 14A-14B illustrate the concept of a welding pixel (wexel)displacement map, in accordance with an embodiment of the presentinvention;

FIG. 15 illustrates an example embodiment of a coupon space and a weldspace of a flat welding coupon (WC) simulated in the system of FIG. 1;

FIG. 16 illustrates an example embodiment of a coupon space and a weldspace of a corner (tee joint) welding coupon (WC) simulated in thesystem of FIG. 1;

FIG. 17 illustrates an example embodiment of a coupon space and a weldspace of a pipe welding coupon (WC) simulated in the system of FIG. 1;

FIG. 18 illustrates an example embodiment of the pipe welding coupon(WC) of FIG. 17; and

FIGS. 19A-19C illustrate an example embodiment of the concept of adual-displacement puddle model of the system of FIG. 1.

DETAILED DESCRIPTION

An embodiment of the present invention comprises a virtual reality arcwelding (VRAW) system comprising a programmable processor-basedsubsystem, a spatial tracker operatively connected to the programmableprocessor-based subsystem, at least one mock welding tool capable ofbeing spatially tracked by the spatial tracker, and at least one displaydevice operatively connected to the programmable processor-basedsubsystem. The system is capable of simulating, in a virtual realityspace, a weld puddle having real-time molten metal fluidity and heatdissipation characteristics. The system is also capable of displayingthe simulated weld puddle on the display device in real-time. Thereal-time molten metal fluidity and heat dissipation characteristics ofthe simulated weld puddle provide real-time visual feedback to a user ofthe mock welding tool when displayed, allowing the user to adjust ormaintain a welding technique in real-time in response to the real-timevisual feedback (i.e., helps the user learn to weld correctly). Thedisplayed weld puddle is representative of a weld puddle that would beformed in the real-world based on the user's welding technique and theselected welding process and parameters. By viewing a puddle (e.g.,shape, color, slag, size, stacked dimes), a user can modify histechnique to make a good weld and determine the type of welding beingdone. The shape of the puddle is responsive to the movement of the gunor stick. As used herein, the term “real-time” means perceiving andexperiencing in time in a simulated environment in the same way that auser would perceive and experience in a real-world welding scenario.Furthermore, the weld puddle is responsive to the effects of thephysical environment including gravity, allowing a user to realisticallypractice welding in various positions including overhead welding andvarious pipe welding angles (e.g., 1 G, 2 G, 5 G, 6 G).

FIG. 1 illustrates an example embodiment of a system block diagram of asystem 100 providing arc welding training in a real-time virtual realityenvironment. The system 100 includes a programmable processor-basedsubsystem (PPS) 110. The system 100 further includes a spatial tracker(ST) 120 operatively connected to the PPS 110. The system 100 alsoincludes a physical welding user interface (WUI) 130 operativelyconnected to the PPS 110 and a face-mounted display device (FMDD) 140operatively connected to the PPS 110 and the ST 120. The system 100further includes an observer display device (ODD) 150 operativelyconnected to the PPS 110. The system 100 also includes at least one mockwelding tool (MWT) 160 operatively connected to the ST 120 and the PPS110. The system 100 further includes a table/stand (T/S) 170 and atleast one welding coupon (WC) 180 capable of being attached to the T/S170. In accordance with an alternative embodiment of the presentinvention, a mock gas bottle is provided (not shown) simulating a sourceof shielding gas and having an adjustable flow regulator.

FIG. 2 illustrates an example embodiment of a combined simulated weldingconsole 135 (simulating a welding power source user interface) andobserver display device (ODD) 150 of the system 100 of FIG. 1. Thephysical WUI 130 resides on a front portion of the console 135 andprovides knobs, buttons, and a joystick for user selection of variousmodes and functions. The ODD 150 is attached to a top portion of theconsole 135. The MWT 160 rests in a holder attached to a side portion ofthe console 135. Internally, the console 135 holds the PPS 110 and aportion of the ST 120.

FIG. 3 illustrates an example embodiment of the observer display device(ODD) 150 of FIG. 2. In accordance with an embodiment of the presentinvention, the ODD 150 is a liquid crystal display (LCD) device. Otherdisplay devices are possible as well. For example, the ODD 150 may be atouchscreen display, in accordance with another embodiment of thepresent invention. The ODD 150 receives video (e.g., SVGA format) anddisplay information from the PPS 110.

As shown in FIG. 3, the ODD 150 is capable of displaying a first userscene showing various welding parameters 151 including position, tip towork, weld angle, travel angle, and travel speed. These parameters maybe selected and displayed in real time in graphical form and are used toteach proper welding technique. Furthermore, as shown in FIG. 3, the ODD150 is capable of displaying simulated welding discontinuity states 152including, for example, improper weld size, poor bead placement, concavebead, excessive convexity, undercut, porosity, incomplete fusion, slaginclusion, excess spatter, overfill, and burnthrough (melt through).Undercut is a groove melted into the base metal adjacent to the weld orweld root and left unfilled by weld metal. Undercut is often due to anincorrect angle of welding. Porosity is cavity type discontinuitiesformed by gas entrapment during solidification often caused by movingthe arc too far away from the coupon.

Also, as shown in FIG. 3, the ODD 50 is capable of displaying userselections 153 including menu, actions, visual cues, new coupon, and endpass. These user selections are tied to user buttons on the console 135.As a user makes various selections via, for example, a touchscreen ofthe ODD 150 or via the physical WUI 130, the displayed characteristicscan change to provide selected information and other options to theuser. Furthermore, the ODD 150 may display a view seen by a welderwearing the FMDD 140 at the same angular view of the welder or atvarious different angles, for example, chosen by an instructor. The ODD150 may be viewed by an instructor and/or students for various trainingpurposes. For example, the view may be rotated around the finished weldallowing visual inspection by an instructor. In accordance with analternate embodiment of the present invention, video from the system 100may be sent to a remote location via, for example, the Internet forremote viewing and/or critiquing. Furthermore, audio may be provided,allowing real-time audio communication between a student and a remoteinstructor.

FIG. 4 illustrates an example embodiment of a front portion of thesimulated welding console 135 of FIG. 2 showing a physical welding userinterface (WUI) 130. The WUI 130 includes a set of buttons 131corresponding to the user selections 153 displayed on the ODD 150. Thebuttons 131 are colored to correspond to the colors of the userselections 153 displayed on the ODD 150. When one of the buttons 131 ispressed, a signal is sent to the PPS 110 to activate the correspondingfunction. The WUI 130 also includes a joystick 132 capable of being usedby a user to select various parameters and selections displayed on theODD 150. The WUI 130 further includes a dial or knob 133 for adjustingwire feed speed/amps, and another dial or knob 134 for adjustingvolts/trim. The WUI 130 also includes a dial or knob 136 for selectingan arc welding process. In accordance with an embodiment of the presentinvention, three arc welding processes are selectable including fluxcored arc welding (FCAW) including gas-shielded and self-shieldedprocesses; gas metal arc welding (GMAW) including short arc, axialspray, STT, and pulse; gas tungsten arc welding (GTAW); and shieldedmetal arc welding (SMAW) including E6010 and E7010 electrodes. The WUI130 further includes a dial or knob 137 for selecting a weldingpolarity. In accordance with an embodiment of the present invention,three arc welding polarities are selectable including alternatingcurrent (AC), positive direct current (DC+), and negative direct current(DC−).

FIG. 5 illustrates an example embodiment of a mock welding tool (MWT)160 of the system 100 of FIG. 1. The MWT 160 of FIG. 5 simulates a stickwelding tool for plate and pipe welding and includes a holder 161 and asimulated stick electrode 162. A trigger on the MWD 160 is used tocommunicate a signal to the PPS 110 to activate a selected simulatedwelding process. The simulated stick electrode 162 includes a tactilelyresistive tip 163 to simulate resistive feedback that occurs during, forexample, a root pass welding procedure in real-world pipe welding orwhen welding a plate. If the user moves the simulated stick electrode162 too far back out of the root, the user will be able to feel or sensethe lower resistance, thereby deriving feedback for use in adjusting ormaintaining the current welding process.

It is contemplated that the stick welding tool may incorporate anactuator, not shown, that withdraws the simulated stick electrode 162during the virtual welding process. That is to say that as a userengages in virtual welding activity, the distance between holder 161 andthe tip of the simulated stick electrode 162 is reduced to simulateconsumption of the electrode. The consumption rate, i.e. withdrawal ofthe stick electrode 162, may be controlled by the PPS 110 and morespecifically by coded instructions executed by the PPS 110. Thesimulated consumption rate may also depend on the user's technique. Itis noteworthy to mention here that as the system 100 facilitates virtualwelding with different types of electrodes, the consumption rate orreduction of the stick electrode 162 may change with the weldingprocedure used and/or setup of the system 100.

Other mock welding tools are possible as well, in accordance with otherembodiments of the present invention, including a MWD that simulates ahand-held semi-automatic welding gun having a wire electrode fed throughthe gun, for example. Furthermore, in accordance with other certainembodiments of the present invention, a real welding tool could be usedas the MWT 160 to better simulate the actual feel of the tool in theuser's hands, even though, in the system 100, the tool would not be usedto actually create a real arc. Also, a simulated grinding tool may beprovided, for use in a simulated grinding mode of the simulator 100.Similarly, a simulated cutting tool may be provided, for use in asimulated cutting mode of the simulator 100. Furthermore, a simulatedgas tungsten arc welding (GTAW) torch or filler material may be providedfor use in the simulator 100.

FIG. 6 illustrates an example embodiment of a table/stand (T/S) 170 ofthe system 100 of FIG. 1. The T/S 170 includes an adjustable table 171,a stand or base 172, an adjustable arm 173, and a vertical post 174. Thetable 171, the stand 172, and the arm 173 are each attached to thevertical post 174. The table 171 and the arm 173 are each capable ofbeing manually adjusted upward, downward, and rotationally with respectto the vertical post 174. The arm 173 is used to hold various weldingcoupons (e.g., welding coupon 175) and a user may rest his/her arm onthe table 171 when training. The vertical post 174 is indexed withposition information such that a user may know exactly where the arm 173and the table 171 are vertically positioned on the post 171. Thisvertical position information may be entered into the system by a userusing the WUI 130 and the ODD 150.

In accordance with an alternative embodiment of the present invention,the positions of the table 171 and the arm 173 may be automatically setby the PSS 110 via preprogrammed settings, or via the WUI 130 and/or theODD 150 as commanded by a user. In such an alternative embodiment, theT/S 170 includes, for example, motors and/or servo-mechanisms, andsignal commands from the PPS 110 activate the motors and/orservo-mechanisms. In accordance with a further alternative embodiment ofthe present invention, the positions of the table 171 and the arm 173and the type of coupon are detected by the system 100. In this way, auser does not have to manually input the position information via theuser interface. In such an alternative embodiment, the T/S 170 includesposition and orientation detectors and sends signal commands to the PPS110 to provide position and orientation information, and the WC 175includes position detecting sensors (e.g., coiled sensors for detectingmagnetic fields). A user is able to see a rendering of the T/S 170adjust on the ODD 150 as the adjustment parameters are changed, inaccordance with an embodiment of the present invention.

FIG. 7A illustrates an example embodiment of a pipe welding coupon (WC)175 of the system 100 of FIG. 1. The WC 175 simulates two six inchdiameter pipes 175′ and 175″ placed together to form a root 176 to bewelded. The WC 175 includes a connection portion 177 at one end of theWC 175, allowing the WC 175 to be attached in a precise and repeatablemanner to the arm 173. FIG. 7B illustrates the pipe WC 175 of FIG. 7Amounted on the arm 173 of the table/stand (TS) 170 of FIG. 6. Theprecise and repeatable manner in which the WC 175 is capable of beingattached to the arm 173 allows for spatial calibration of the WC 175 tobe performed only once at the factory. Then, in the field, as long asthe system 100 is told the position of the arm 173, the system 100 isable to track the MWT 160 and the FMDD 140 with respect to the WC 175 ina virtual environment. A first portion of the arm 173, to which the WC175 is attached, is capable of being tilted with respect to a secondportion of the arm 173, as shown in FIG. 6. This allows the user topractice pipe welding with the pipe in any of several differentorientations and angles.

FIG. 8 illustrates various elements of an example embodiment of thespatial tracker (ST) 120 of FIG. 1. The ST 120 is a magnetic trackerthat is capable of operatively interfacing with the PPS 110 of thesystem 100. The ST 120 includes a magnetic source 121 and source cable,at least one sensor 122 and associated cable, host software on disk 123,a power source 124 and associated cable, USB and RS-232 cables 125, anda processor tracking unit 126. The magnetic source 121 is capable ofbeing operatively connected to the processor tracking unit 126 via acable. The sensor 122 is capable of being operatively connected to theprocessor tracking unit 126 via a cable. The power source 124 is capableof being operatively connected to the processor tracking unit 126 via acable. The processor tracking unit 126 is cable of being operativelyconnected to the PPS 110 via a USB or RS-232 cable 125. The hostsoftware on disk 123 is capable of being loaded onto the PPS 110 andallows functional communication between the ST 120 and the PPS 110.

Referring to FIG. 6, the magnetic source 121 of the ST 120 is mounted onthe first portion of the arm 173. The magnetic source 121 creates amagnetic field around the source 121, including the space encompassingthe WC 175 attached to the arm 173, which establishes a 3D spatial frameof reference. The T/S 170 is largely non-metallic (non-ferric andnon-conductive) so as not to distort the magnetic field created by themagnetic source 121. The sensor 122 includes three induction coilsorthogonally aligned along three spatial directions. The induction coilsof the sensor 122 each measure the strength of the magnetic field ineach of the three directions and provide that information to theprocessor tracking unit 126. As a result, the system 100 is able to knowwhere any portion of the WC 175 is with respect to the 3D spatial frameof reference established by the magnetic field when the WC 175 ismounted on the arm 173. The sensor 122 may be attached to the MWT 160 orto the FMDD 140, allowing the MWT 160 or the FMDD 140 to be tracked bythe ST 120 with respect to the 3D spatial frame of reference in bothspace and orientation. When two sensors 122 are provided and operativelyconnected to the processor tracking unit 126, both the MWT 160 and theFMDD 140 may be tracked. In this manner, the system 100 is capable ofcreating a virtual WC, a virtual MWT, and a virtual T/S in virtualreality space and displaying the virtual WC, the virtual MWT, and thevirtual T/S on the FMDD 140 and/or the ODD 150 as the MWT 160 and theFMDD 140 are tracked with respect to the 3D spatial frame of reference.

In accordance with an alternative embodiment of the present invention,the sensor(s) 122 may wirelessly interface to the processor trackingunit 126, and the processor tracking unit 126 may wirelessly interfaceto the PPS 110. In accordance with other alternative embodiments of thepresent invention, other types of spatial trackers 120 may be used inthe system 100 including, for example, an accelerometer/gyroscope-basedtracker, an optical tracker (active or passive), an infrared tracker, anacoustic tracker, a laser tracker, a radio frequency tracker, aninertial tracker, and augmented reality based tracking systems. Othertypes of trackers may be possible as well.

FIG. 9A illustrates an example embodiment of the face-mounted displaydevice 140 (FMDD) of the system 100 of FIG. 1. FIG. 9B is anillustration of how the FMDD 140 of FIG. 9A is secured on the head of auser. FIG. 9C illustrates an example embodiment of the FMDD 140 of FIG.9A integrated into a welding helmet 900. The FMDD 140 operativelyconnects to the PPS 110 and the ST 120 either via wired means orwirelessly. A sensor 122 of the ST 120 may be attached to the FMDD 140or to the welding helmet 900, in accordance with various embodiments ofthe present invention, allowing the FMDD 140 and/or welding helmet 900to be tracked with respect to the 3D spatial frame of reference createdby the ST 120.

In accordance with an embodiment of the present invention, the FMDD 140includes two high-contrast SVGA 3D OLED microdisplays capable ofdelivering fluid full-motion video in the 2D and frame sequential videomodes. Video of the virtual reality environment is provided anddisplayed on the FMDD 140. A zoom (e.g., 2×) mode may be provided,allowing a user to simulate a cheater lens, for example.

The FMDD 140 further includes two earbud speakers 910, allowing the userto hear simulated welding-related and environmental sounds produced bythe system 100. The FMDD 140 may operatively interface to the PPS 110via wired or wireless means, in accordance with various embodiments ofthe present invention. In accordance with an embodiment of the presentinvention, the PPS 110 provides stereoscopic video to the FMDD 140,providing enhanced depth perception to the user. In accordance with analternate embodiment of the present invention, a user is able to use acontrol on the MWT 160 (e.g., a button or switch) to call up and selectmenus and display options on the FMDD 140. This may allow the user toeasily reset a weld if he makes a mistake, change certain parameters, orback up a little to re-do a portion of a weld bead trajectory, forexample.

FIG. 10 illustrates an example embodiment of a subsystem block diagramof the programmable processor-based subsystem (PPS) 110 of the system100 of FIG. 1. The PPS 110 includes a central processing unit (CPU) 111and two graphics processing units (GPU) 115, in accordance with anembodiment of the present invention. The two GPUs 115 are programmed toprovide virtual reality simulation of a weld puddle (a.k.a. a weld pool)having real-time molten metal fluidity and heat absorption anddissipation characteristics, in accordance with an embodiment of thepresent invention.

FIG. 11 illustrates an example embodiment of a block diagram of agraphics processing unit (GPU) 115 of the PPS 110 of FIG. 10. Each GPU115 supports the implementation of data parallel algorithms. Inaccordance with an embodiment of the present invention, each GPU 115provides two video outputs 118 and 119 capable of providing two virtualreality views. Two of the video outputs may be routed to the FMDD 140,rendering the welder's point of view, and a third video output may berouted to the ODD 150, for example, rendering either the welder's pointof view or some other point of view. The remaining fourth video outputmay be routed to a projector, for example. Both GPUs 115 perform thesame welding physics computations but may render the virtual realityenvironment from the same or different points of view. The GPU 115includes a compute unified device architecture (CUDA) 116 and a shader117. The CUDA 116 is the computing engine of the GPU 115 which isaccessible to software developers through industry standard programminglanguages. The CUDA 116 includes parallel cores and is used to run thephysics model of the weld puddle simulation described herein. The CPU111 provides real-time welding input data to the CUDA 116 on the GPU115. The shader 117 is responsible for drawing and applying all of thevisuals of the simulation. Bead and puddle visuals are driven by thestate of a wexel displacement map which is described later herein. Inaccordance with an embodiment of the present invention, the physicsmodel runs and updates at a rate of about 30 times per second.

FIG. 12 illustrates an example embodiment of a functional block diagramof the system 100 of FIG. 1. The various functional blocks of the system100 as shown in FIG. 12 are implemented largely via softwareinstructions and modules running on the PPS 110. The various functionalblocks of the system 100 include a physical interface 1201, torch andclamp models 1202, environment models 1203, sound content functionality1204, welding sounds 1205, stand/table model 1206, internal architecturefunctionality 1207, calibration functionality 1208, coupon models 1210,welding physics 1211, internal physics adjustment tool (tweaker) 1212,graphical user interface functionality 1213, graphing functionality1214, student reports functionality 1215, renderer 1216, bead rendering1217, 3D textures 1218, visual cues functionality 1219, scoring andtolerance functionality 1220, tolerance editor 1221, and special effects1222.

The internal architecture functionality 1207 provides the higher levelsoftware logistics of the processes of the system 100 including, forexample, loading files, holding information, managing threads, turningthe physics model on, and triggering menus. The internal architecturefunctionality 1207 runs on the CPU 111, in accordance with an embodimentof the present invention. Certain real-time inputs to the PPS 110include arc location, gun position, FMDD or helmet position, gun on/offstate, and contact made state (yes/no).

The graphical user interface functionality 1213 allows a user, throughthe ODD 150 using the joystick 132 of the physical user interface 130,to set up a welding scenario. In accordance with an embodiment of thepresent invention, the set up of a welding scenario includes selecting alanguage, entering a user name, selecting a practice plate (i.e., awelding coupon), selecting a welding process (e.g., FCAW, GMAW, SMAW)and associated axial spray, pulse, or short arc methods, selecting a gastype and flow rate, selecting a type of stick electrode (e.g., 6010 or7018), and selecting a type of flux cored wire (e.g., self-shielded,gas-shielded). The set up of a welding scenario also includes selectinga table height, an arm height, an arm position, and an arm rotation ofthe T/S 170. The set up of a welding scenario further includes selectingan environment (e.g., a background environment in virtual realityspace), setting a wire feed speed, setting a voltage level, setting anamperage, selecting a polarity, and turning particular visual cues on oroff.

During a simulated welding scenario, the graphing functionality 1214gathers user performance parameters and provides the user performanceparameters to the graphical user interface functionality 1213 fordisplay in a graphical format (e.g., on the ODD 150). Trackinginformation from the ST 120 feeds into the graphing functionality 1214.The graphing functionality 1214 includes a simple analysis module (SAM)and a whip/weave analysis module (WWAM). The SAM analyzes user weldingparameters including welding travel angle, travel speed, weld angle,position, and tip to work distance by comparing the welding parametersto data stored in bead tables. The WWAM analyzes user whippingparameters including dime spacing, whip time, and puddle time. The WWAMalso analyzes user weaving parameters including width of weave, weavespacing, and weave timing. The SAM and WWAM interpret raw input data(e.g., position and orientation data) into functionally usable data forgraphing. For each parameter analyzed by the SAM and the WWAM, atolerance window is defined by parameter limits around an optimum orideal set point input into bead tables using the tolerance editor 1221,and scoring and tolerance functionality 1220 is performed.

The tolerance editor 1221 includes a weldometer which approximatesmaterial usage, electrical usage, and welding time. Furthermore, whencertain parameters are out of tolerance, welding discontinuities (i.e.,welding defects) may occur. The state of any welding discontinuities areprocessed by the graphing functionality 1214 and presented via thegraphical user interface functionality 1213 in a graphical format. Suchwelding discontinuities include improper weld size, poor bead placement,concave bead, excessive convexity, undercut, porosity, incompletefusion, slag entrapment, overfill, burnthrough, and excessive spatter.In accordance with an embodiment of the present invention, the level oramount of a discontinuity is dependent on how far away a particular userparameter is from the optimum or ideal set point.

Different parameter limits may be pre-defined for different types ofusers such as, for example, welding novices, welding experts, andpersons at a trade show. The scoring and tolerance functionality 1220provide number scores depending on how close to optimum (ideal) a useris for a particular parameter and depending on the level ofdiscontinuities or defects present in the weld. The optimum values arederived from real-world data. Information from the scoring and tolerancefunctionality 1220 and from the graphics functionality 1214 may be usedby the student reports functionality 1215 to create a performance reportfor an instructor and/or a student.

The system 100 is capable of analyzing and displaying the results ofvirtual welding activity. By analyzing the results, it is meant thatsystem 100 is capable of determining when during the welding pass andwhere along the weld joints, the user deviated from the acceptablelimits of the welding process. A score may be attributed to the user'sperformance. In one embodiment, the score may be a function of deviationin position, orientation and speed of the mock welding tool 160 throughranges of tolerances, which may extend from an ideal welding pass tomarginal or unacceptable welding activity. Any gradient of ranges may beincorporated into the system 100 as chosen for scoring the user'sperformance. Scoring may be displayed numerically or alpha-numerically.Additionally, the user's performance may be displayed graphicallyshowing, in time and/or position along the weld joint, how closely themock welding tool traversed the weld joint. Parameters such as travelangle, work angle, speed, and distance from the weld joint are examplesof what may be measured, although any parameters may be analyzed forscoring purposes. The tolerance ranges of the parameters are taken fromreal-world welding data, thereby providing accurate feedback as to howthe user will perform in the real world. In another embodiment, analysisof the defects corresponding to the user's performance may also beincorporated and displayed on the ODD 150. In this embodiment, a graphmay be depicted indicating what type of discontinuity resulted frommeasuring the various parameters monitored during the virtual weldingactivity. While occlusions may not be visible on the ODD 150, defectsmay still have occurred as a result of the user's performance, theresults of which may still be correspondingly displayed, i.e. graphed.

Visual cues functionality 1219 provide immediate feedback to the user bydisplaying overlaid colors and indicators on the FMDD 140 and/or the ODD150. Visual cues are provided for each of the welding parameters 151including position, tip to work distance, weld angle, travel angle,travel speed, and arc length (e.g., for stick welding) and visuallyindicate to the user if some aspect of the user's welding techniqueshould be adjusted based on the predefined limits or tolerances. Visualcues may also be provided for whip/weave technique and weld bead “dime”spacing, for example. Visual cues may be set independently or in anydesired combination.

Calibration functionality 1208 provides the capability to match upphysical components in real world space (3D frame of reference) withvisual components in virtual reality space. Each different type ofwelding coupon (WC) is calibrated in the factory by mounting the WC tothe arm 173 of the T/S 170 and touching the WC at predefined points(indicated by, for example, three dimples on the WC) with a calibrationstylus operatively connected to the ST 120. The ST 120 reads themagnetic field intensities at the predefined points, provides positioninformation to the PPS 110, and the PPS 110 uses the positioninformation to perform the calibration (i.e., the translation from realworld space to virtual reality space).

Any particular type of WC fits into the arm 173 of the T/S 170 in thesame repeatable way to within very tight tolerances. Therefore, once aparticular WC type is calibrated, that WC type does not have to bere-calibrated (i.e., calibration of a particular type of WC is aone-time event). WCs of the same type are interchangeable. Calibrationensures that physical feedback perceived by the user during a weldingprocess matches up with what is displayed to the user in virtual realityspace, making the simulation seem more real. For example, if the userslides the tip of a MWT 160 around the corner of a actual WC 180, theuser will see the tip sliding around the corner of the virtual WC on theFMDD 140 as the user feels the tip sliding around the actual corner. Inaccordance with an embodiment of the present invention, the MWT 160 isplaced in a pre-positioned jig and is calibrated as well, based on theknown jig position.

In accordance with an alternative embodiment of the present invention,“smart” coupons are provided, having sensors on, for example, thecorners of the coupons. The ST 120 is able to track the corners of a“smart” coupon such that the system 100 continuously knows where the“smart” coupon is in real world 3D space. In accordance with a furtheralternative embodiment of the present invention, licensing keys areprovided to “unlock” welding coupons. When a particular WC is purchased,a licensing key is provided allowing the user to enter the licensing keyinto the system 100, unlocking the software associated with that WC. Inaccordance with another embodiment of the present invention, specialnon-standard welding coupons may be provided based on real-world CADdrawings of parts. Users may be able to train on welding a CAD part evenbefore the part is actually produced in the real world.

Sound content functionality 1204 and welding sounds 1205 provideparticular types of welding sounds that change depending on if certainwelding parameters are within tolerance or out of tolerance. Sounds aretailored to the various welding processes and parameters. For example,in a MIG spray arc welding process, a crackling sound is provided whenthe user does not have the MWT 160 positioned correctly, and a hissingsound is provided when the MWT 160 is positioned correctly. In a shortarc welding process, a steady crackling or frying sound is provided forproper welding technique, and a hissing sound may be provided whenundercutting is occurring. These sounds mimic real world soundscorresponding to correct and incorrect welding technique.

High fidelity sound content may be taken from real world recordings ofactual welding using a variety of electronic and mechanical means, inaccordance with various embodiments of the present invention. Inaccordance with an embodiment of the present invention, the perceivedvolume and directionality of sound is modified depending on theposition, orientation, and distance of the user's head (assuming theuser is wearing a FMDD 140 that is tracked by the ST 120) with respectto the simulated arc between the MWT 160 and the WC 180. Sound may beprovided to the user via ear bud speakers 910 in the FMDD 140 or viaspeakers configured in the console 135 or T/S 170, for example.

Environment models 1203 are provided to provide various backgroundscenes (still and moving) in virtual reality space. Such backgroundenvironments may include, for example, an indoor welding shop, anoutdoor race track, a garage, etc. and may include moving cars, people,birds, clouds, and various environmental sounds. The backgroundenvironment may be interactive, in accordance with an embodiment of thepresent invention. For example, a user may have to survey a backgroundarea, before starting welding, to ensure that the environment isappropriate (e.g., safe) for welding. Torch and clamp models 1202 areprovided which model various MWTs 160 including, for example, guns,holders with stick electrodes, etc. in virtual reality space.

Coupon models 1210 are provided which model various WCs 180 including,for example, flat plate coupons, T-joint coupons, butt-joint coupons,groove-weld coupons, and pipe coupons (e.g., 2-inch diameter pipe and6-inch diameter pipe) in virtual reality space. A stand/table model 1206is provided which models the various parts of the T/S 170 including anadjustable table 171, a stand 172, an adjustable arm 173, and a verticalpost 174 in virtual reality space. A physical interface model 1201 isprovided which models the various parts of the welding user interface130, console 135, and ODD 150 in virtual reality space.

In accordance with an embodiment of the present invention, simulation ofa weld puddle or pool in virtual reality space is accomplished where thesimulated weld puddle has real-time molten metal fluidity and heatdissipation characteristics. At the heart of the weld puddle simulationis the welding physics functionality 1211 (a.k.a., the physics model)which is run on the GPUs 115, in accordance with an embodiment of thepresent invention. The welding physics functionality employs a doubledisplacement layer technique to accurately model dynamicfluidity/viscosity, solidity, heat gradient (heat absorption anddissipation), puddle wake, and bead shape, and is described in moredetail herein with respect to FIGS. 14A-14C.

The welding physics functionality 1211 communicates with the beadrendering functionality 1217 to render a weld bead in all states fromthe heated molten state to the cooled solidified state. The beadrendering functionality 1217 uses information from the welding physicsfunctionality 1211 (e.g., heat, fluidity, displacement, dime spacing) toaccurately and realistically render a weld bead in virtual reality spacein real-time. The 3D textures functionality 1218 provides texture mapsto the bead rendering functionality 1217 to overlay additional textures(e.g., scorching, slag, grain) onto the simulated weld bead. Forexample, slag may be shown rendered over a weld bead during and justafter a welding process, and then removed to reveal the underlying weldbead. The renderer functionality 1216 is used to render variousnon-puddle specific characteristics using information from the specialeffects module 1222 including sparks, spatter; smoke, arc glow, fumesand gases, and certain discontinuities such as, for example, undercutand porosity.

The internal physics adjustment tool 1212 is a tweaking tool that allowsvarious welding physics parameters to be defined, updated, and modifiedfor the various welding processes. In accordance with an embodiment ofthe present invention, the internal physics adjustment tool 1212 runs onthe CPU 111 and the adjusted or updated parameters are downloaded to theGPUs 115. The types of parameters that may be adjusted via the internalphysics adjustment tool 1212 include parameters related to weldingcoupons, process parameters that allow a process to be changed withouthaving to reset a welding coupon (allows for doing a second pass),various global parameters that can be changed without resetting theentire simulation, and other various parameters.

FIG. 13 is a flow chart of an embodiment of a method 1300 of trainingusing the virtual reality training system 100 of FIG. 1. In step 1310,move a mock welding tool with respect to a welding coupon in accordancewith a welding technique. In step 1320, track position and orientationof the mock welding tool in three-dimensional space using a virtualreality system. In step 1330, view a display of the virtual realitywelding system showing a real-time virtual reality simulation of themock welding tool and the welding coupon in a virtual reality space asthe simulated mock welding tool deposits a simulated weld bead materialonto at least one simulated surface of the simulated welding coupon byforming a simulated weld puddle in the vicinity of a simulated arcemitting from said simulated mock welding tool. In step 1340, view onthe display, real-time molten metal fluidity and heat dissipationcharacteristics of the simulated weld puddle. In step 1350, modify inreal-time, at least one aspect of the welding technique in response toviewing the real-time molten metal fluidity and heat dissipationcharacteristics of the simulated weld puddle.

The method 1300 illustrates how a user is able to view a weld puddle invirtual reality space and modify his welding technique in response toviewing various characteristics of the simulated weld puddle, includingreal-time molten metal fluidity (e.g., viscosity) and heat dissipation.The user may also view and respond to other characteristics includingreal-time puddle wake and dime spacing. Viewing and responding tocharacteristics of the weld puddle is how most welding operations areactually performed in the real world. The double displacement layermodeling of the welding physics functionality 1211 run on the GPUs 115allows for such real-time molten metal fluidity and heat dissipationcharacteristics to be accurately modeled and represented to the user.For example, heat dissipation determines solidification time (i.e., howmuch time it takes for a wexel to completely solidify).

Furthermore, a user may make a second pass over the weld bead materialusing the same or a different (e.g., a second) mock welding tool and/orwelding process. In such a second pass scenario, the simulation showsthe simulated mock welding tool, the welding coupon, and the originalsimulated weld bead material in virtual reality space as the simulatedmock welding tool deposits a second simulated weld bead material mergingwith the first simulated weld bead material by forming a secondsimulated weld puddle in the vicinity of a simulated arc emitting fromthe simulated mock welding tool. Additional subsequent passes using thesame or different welding tools or processes may be made in a similarmanner. In any second or subsequent pass, the previous weld beadmaterial is merged with the new weld bead material being deposited as anew weld puddle is formed in virtual reality space from the combinationof any of the previous weld bead material, the new weld bead material,and possibly the underlying coupon material in accordance with certainembodiments of the present invention. Such subsequent passes may beneeded to make a large fillet or groove weld, performed to repair a weldbead formed by a previous pass, for example, or may include a hot passand one or more fill and cap passes after a root pass as is done in pipewelding. In accordance with various embodiments of the presentinvention, weld bead and base material may include mild steel, stainlesssteel, aluminum, nickel based alloys, or other materials.

FIGS. 14A-14B illustrate the concept of a welding element (wexel)displacement map 1420, in accordance with an embodiment of the presentinvention. FIG. 14A shows a side view of a flat welding coupon (WC) 1400having a flat top surface 1410. The welding coupon 1400 exists in thereal world as, for example, a plastic part, and also exists in virtualreality space as a simulated welding coupon. FIG. 14B shows arepresentation of the top surface 1410 of the simulated WC 1400 brokenup into a grid or array of welding elements (i.e., wexels) forming awexel map 1420. Each wexel (e.g., wexel 1421) defines a small portion ofthe surface 1410 of the welding coupon. The wexel map defines thesurface resolution. Changeable channel parameter values are assigned toeach wexel, allowing values of each wexel to dynamically change inreal-time in virtual reality weld space during a simulated weldingprocess. The changeable channel parameter values correspond to thechannels Puddle (molten metal fluidity/viscosity displacement), Heat(heat absorption/dissipation), Displacement (solid displacement), andExtra (various extra states, e.g., slag, grain, scorching, virginmetal). These changeable channels are referred to herein as PHED forPuddle, Heat, Extra, and Displacement, respectively.

FIG. 15 illustrates an example embodiment of a coupon space and a weldspace of the flat welding coupon (WC) 1400 of FIG. 14 simulated in thesystem 100 of FIG. 1. Points O, X, Y, and Z define the local 3D couponspace. In general, each coupon type defines the mapping from 3D couponspace to 2D virtual reality weld space. The wexel map 1420 of FIG. 14 isa two-dimensional array of values that map to weld space in virtualreality. A user is to weld from point B to point E as shown in FIG. 15.A trajectory line from point B to point E is shown in both 3D couponspace and 2D weld space in FIG. 15.

Each type of coupon defines the direction of displacement for eachlocation in the wexel map. For the flat welding coupon of FIG. 15, thedirection of displacement is the same at all locations in the wexel map(i.e., in the Z-direction). The texture coordinates of the wexel map areshown as S, T (sometimes called U, V) in both 3D coupon space and 2Dweld space, in order to clarify the mapping. The wexel map is mapped toand represents the rectangular surface 1410 of the welding coupon 1400.

FIG. 16 illustrates an example embodiment of a coupon space and a weldspace of a corner (tee joint) welding coupon (WC) 1600 simulated in thesystem 100 of FIG. 1. The corner WC 1600 has two surfaces 1610 and 1620in 3D coupon space that are mapped to 2D weld space as shown in FIG. 16.Again, points O, X, Y, and Z define the local 3D coupon space. Thetexture coordinates of the wexel map are shown as S, T in both 3D couponspace and 2D weld space, in order to clarify the mapping. A user is toweld from point B to point E as shown in FIG. 16. A trajectory line frompoint B to point E is shown in both 3D coupon space and 2D weld space inFIG. 16. However, the direction of displacement is towards the lineX′-O′ as shown in the 3D coupon space, towards the opposite corner asshown in FIG. 16.

FIG. 17 illustrates an example embodiment of a coupon space and a weldspace of a pipe welding coupon (WC) 1700 simulated in the system 100 ofFIG. 1. The pipe WC 1700 has a curved surface 1710 in 3D coupon spacethat is mapped to 2D weld space as shown in FIG. 17. Again, points O, X,Y, and Z define the local 3D coupon space. The texture coordinates ofthe wexel map are shown as S, T in both 3D coupon space and 2D weldspace, in order to clarify the mapping. A user is to weld from point Bto point E along a curved trajectory as shown in FIG. 17. A trajectorycurve and line from point B to point E is shown in 3D coupon space and2D weld space, respectively, in FIG. 17. The direction of displacementis away from the line Y-O (i.e., away from the center of the pipe). FIG.18 illustrates an example embodiment of the pipe welding coupon (WC)1700 of FIG. 17. The pipe WC 1700 is made of a non-ferric,non-conductive plastic and simulates two pipe pieces 1701 and 1702coming together to form a root joint 1703. An attachment piece 1704 forattaching to the arm 173 of the T/S 170 is also shown.

In a similar manner that a texture map may be mapped to a rectangularsurface area of a geometry, a weldable wexel map may be mapped to arectangular surface of a welding coupon. Each element of the weldablemap is termed a wexel in the same sense that each element of a pictureis termed a pixel (a contraction of picture element). A pixel containschannels of information that define a color (e.g., red, green, blue,etc.). A wexel contains channels of information (e.g., P, H, E, D) thatdefine a weldable surface in virtual reality space.

In accordance with an embodiment of the present invention, the format ofa wexel is summarized as channels PHED (Puddle, Heat, Extra,Displacement) which contains four floating point numbers. The Extrachannel is treated as a set of bits which store logical informationabout the wexel such as, for example, whether or not there is any slagat the wexel location. The Puddle channel stores a displacement valuefor any liquefied metal at the wexel location. The Displacement channelstores a displacement value for the solidified metal at the wexellocation. The Heat channel stores a value giving the magnitude of heatat the wexel location. In this way, the weldable part of the coupon canshow displacement due to a welded bead, a shimmering surface “puddle”due to liquid metal, color due to heat, etc. All of these effects areachieved by the vertex and pixel shaders applied to the weldablesurface.

In accordance with an embodiment of the present invention, adisplacement map and a particle system are used where the particles caninteract with each other and collide with the displacement map. Theparticles are virtual dynamic fluid particles and provide the liquidbehavior of the weld puddle but are not rendered directly (i.e., are notvisually seen directly). Instead, only the particle effects on thedisplacement map are visually seen. Heat input to a wexel affects themovement of nearby particles. There are two types of displacementinvolved in simulating a welding puddle which include Puddle andDisplacement. Puddle is “temporary” and only lasts as long as there areparticles and heat present. Displacement is “permanent”. Puddledisplacement is the liquid metal of the weld which changes rapidly(e.g., shimmers) and can be thought of as being “on top” of theDisplacement. The particles overlay a portion of a virtual surfacedisplacement map (i.e., a wexel map). The Displacement represents thepermanent solid metal including both the initial base metal and the weldbead that has solidified.

In accordance with an embodiment of the present invention, the simulatedwelding process in virtual reality space works as follows: Particlesstream from the emitter (emitter of the simulated MWT 160) in a thincone. The particles make first contact with the surface of the simulatedwelding coupon where the surface is defined by a wexel map. Theparticles interact with each other and the wexel map and build up inreal-time. More heat is added the nearer a wexel is to the emitter. Heatis modeled in dependence on distance from the arc point and the amountof time that heat is input from the arc. Certain visuals (e.g., color,etc.) are driven by the heat. A weld puddle is drawn or rendered invirtual reality space for wexels having enough heat. Wherever it is hotenough, the wexel map liquefies, causing the Puddle displacement to“raise up” for those wexel locations. Puddle displacement is determinedby sampling the “highest” particles at each wexel location. As theemitter moves on along the weld trajectory, the wexel locations leftbehind cool. Heat is removed from a wexel location at a particular rate.When a cooling threshold is reached, the wexel map solidifies. As such,the Puddle displacement is gradually converted to Displacement (i.e., asolidified bead). Displacement added is equivalent to Puddle removedsuch that the overall height does not change. Particle lifetimes aretweaked or adjusted to persist until solidification is complete. Certainparticle properties that are modeled in the system 100 includeattraction/repulsion, velocity (related to heat), dampening (related toheat dissipation), direction (related to gravity).

FIGS. 19A-19C illustrate an example embodiment of the concept of adual-displacement (displacement and particles) puddle model of thesystem 100 of FIG. 1. Welding coupons are simulated in virtual realityspace having at least one surface. The surfaces of the welding couponare simulated in virtual reality space as a double displacement layerincluding a solid displacement layer and a puddle displacement layer.The puddle displacement layer is capable of modifying the soliddisplacement layer.

As described herein, “puddle” is defined by an area of the wexel mapwhere the Puddle value has been raised up by the presence of particles.The sampling process is represented in FIGS. 19A-19C. A section of awexel map is shown having seven adjacent wexels. The currentDisplacement values are represented by un-shaded rectangular bars 1910of a given height (i.e., a given displacement for each wexel). In FIG.19A, the particles 1920 are shown as round un-shaded dots colliding withthe current Displacement levels and are piled up. In FIG. 19B, the“highest” particle heights 1930 are sampled at each wexel location. InFIG. 19C, the shaded rectangles 1940 show how much Puddle has been addedon top of the Displacement as a result of the particles. The weld puddleheight is not instantly set to the sampled values since Puddle is addedat a particular liquification rate based on Heat. Although not shown inFIGS. 19A-19C, it is possible to visualize the solidification process asthe Puddle (shaded rectangles) gradually shrink and the Displacement(un-shaded rectangles) gradually grow from below to exactly take theplace of the Puddle. In this manner, real-time molten metal fluiditycharacteristics are accurately simulated. As a user practices aparticular welding process, the user is able to observe the molten metalfluidity characteristics and the heat dissipation characteristics of theweld puddle in real-time in virtual reality space and use thisinformation to adjust or maintain his welding technique.

The number of wexels representing the surface of a welding coupon isfixed. Furthermore, the puddle particles that are generated by thesimulation to model fluidity are temporary, as described herein.Therefore, once an initial puddle is generated in virtual reality spaceduring a simulated welding process using the system 100, the number ofwexels plus puddle particles tends to remain relatively constant. Thisis because the number of wexels that are being processed is fixed andthe number of puddle particles that exist and are being processed duringthe welding process tend to remain relatively constant because puddleparticles are being created and “destroyed” at a similar rate (i.e., thepuddle particles are temporary). Therefore, the processing load of thePPS 110 remains relatively constant during a simulated welding session.

In accordance with an alternate embodiment of the present invention,puddle particles may be generated within or below the surface of thewelding coupon. In such an embodiment, displacement may be modeled asbeing positive or negative with respect to the original surfacedisplacement of a virgin (i.e., un-welded) coupon. In this manner,puddle particles may not only build up on the surface of a weldingcoupon, but may also penetrate the welding coupon. However, the numberof wexels is still fixed and the puddle particles being created anddestroyed is still relatively constant.

In accordance with alternate embodiments of the present invention,instead of modeling particles, a wexel displacement map may be providedhaving more channels to model the fluidity of the puddle. Or, instead ofmodeling particles, a dense voxel map may be modeled. Or, instead of awexel map, only particles may be modeled which are sampled and never goaway. Such alternative embodiments may not provide a relatively constantprocessing load for the system, however.

Furthermore, in accordance with an embodiment of the present invention,blowthrough or a keyhole is simulated by taking material away. Forexample, if a user keeps an arc in the same location for too long, inthe real world, the material would burn away causing a hole. Suchreal-world burnthrough is simulated in the system 100 by wexeldecimation techniques. If the amount of heat absorbed by a wexel isdetermined to be too high by the system 100, that wexel may be flaggedor designated as being burned away and rendered as such (e.g., renderedas a hole). Subsequently, however, wexel reconstitution may occur forcertain welding process (e.g., pipe welding) where material is addedback after being initially burned away. In general, the system 100simulates wexel decimation (taking material away) and wexelreconstitution (i.e., adding material back). Furthermore, removingmaterial in root-pass welding is properly simulated in the system 100.

Furthermore, removing material in root-pass welding is properlysimulated in the system 100. For example, in the real world, grinding ofthe root pass may be performed prior to subsequent welding passes.Similarly, system 100 may simulate a grinding pass that removes materialfrom the virtual weld joint. It will be appreciated that the materialremoved may be modeled as a negative displacement on the wexel map. Thatis to say that the grinding pass removes material that is modeled by thesystem 100 resulting in an altered bead contour. Simulation of thegrinding pass may be automatic, which is to say that the system 100removes a predetermined thickness of material, which may be respectiveto the surface of the root pass weld bead.

In an alternative embodiment, an actual grinding tool, or grinder, maybe simulated that turns on and off by activation of the mock weldingtool 160 or another input device. It is noted that the grinding tool maybe simulated to resemble a real world grinder. In this embodiment, theuser maneuvers the grinding tool along the root pass to remove materialresponsive to the movement thereof. It will be understood that the usermay be allowed to remove too much material. In a manner similar to thatdescribed above, holes or other defects (described above) may result ifthe user grinds away too much material. Still, hard limits or stops maybe implemented, i.e. programmed, to prevent the user from removing toomuch material or indicate when too much material is being removed.

In addition to the non-visible “puddle” particles described herein, thesystem 100 also uses three other types of visible particles to representArc, Flame, and Spark effects, in accordance with an embodiment of thepresent invention. These types of particles do not interact with otherparticles of any type but interact only with the displacement map. Whilethese particles do collide with the simulated weld surface, they do notinteract with each other. Only Puddle particles interact with eachother, in accordance with an embodiment of the present invention. Thephysics of the Spark particles is setup such that the Spark particlesbounce around and are rendered as glowing dots in virtual reality space.

The physics of the Arc particles is setup such that the Arc particleshit the surface of the simulated coupon or weld bead and stay for awhile. The Arc particles are rendered as larger dim bluish-white spotsin virtual reality space. It takes many such spots superimposed to formany sort of visual image. The end result is a white glowing nimbus withblue edges.

The physics of the Flame particles is modeled to slowly raise upward.The Flame particles are rendered as medium sized dim red-yellow spots.It takes many such spots superimposed to form any sort of visual image.The end result is blobs of orange-red flames with red edges raisingupward and fading out. Other types of non-puddle particles may beimplemented in the system 100, in accordance with other embodiments ofthe present invention. For example, smoke particles may be modeled andsimulated in a similar manner to flame particles.

The final steps in the simulated visualization are handled by the vertexand pixel shaders provided by the shaders 117 of the GPUs 115. Thevertex and pixel shaders apply Puddle and Displacement, as well assurface colors and reflectivity altered due to heat, etc. The Extra (E)channel of the PHED wexel format, as discussed earlier herein, containsall of the extra information used per wexel. In accordance with anembodiment of the present invention, the extra information includes anon virgin bit (true=bead, false=virgin steel), a slag bit, an undercutvalue (amount of undercut at this wexel where zero equals no undercut),a porosity value (amount of porosity at this wexel where zero equals noporosity), and a bead wake value which encodes the time at which thebead solidifies. There are a set of image maps associated with differentcoupon visuals including virgin steel, slag, bead, and porosity. Theseimage maps are used both for bump mapping and texture mapping. Theamount of blending of these image maps is controlled by the variousflags and values described herein.

A bead wake effect is achieved using a 1D image map and a per wexel beadwake value that encodes the time at which a given bit of bead issolidified. Once a hot puddle wexel location is no longer hot enough tobe called “puddle”, a time is saved at that location and is called “beadwake”. The end result is that the shader code is able to use the 1Dtexture map to draw the “ripples” that give a bead its unique appearancewhich portrays the direction in which the bead was laid down. Inaccordance with an alternative embodiment of the present invention, thesystem 100 is capable of simulating, in virtual reality space, anddisplaying a weld bead having a real-time weld bead wake characteristicresulting from a real-time fluidity-to-solidification transition of thesimulated weld puddle, as the simulated weld puddle is moved along aweld trajectory.

In accordance with an alternative embodiment of the present invention,the system 100 is capable of teaching a user how to troubleshoot awelding machine. For example, a troubleshooting mode of the system maytrain a user to make sure he sets up the system correctly (e.g., correctgas flow rate, correct power cord connected, etc.) In accordance withanother alternate embodiment of the present invention, the system 100 iscapable of recording and playing back a welding session (or at least aportion of a welding session, for example, N frames). A track ball maybe provided to scroll through frames of video, allowing a user orinstructor to critique a welding session. Playback may be provided atselectable speeds as well (e.g., full speed, half speed, quarter speed).In accordance with an embodiment of the present invention, asplit-screen playback may be provided, allowing two welding sessions tobe viewed side-by-side, for example, on the ODD 150. For example, a“good” welding session may be viewed next to a “poor” welding sessionfor comparison purposes.

In summary, disclosed is a real-time virtual reality welding systemincluding a programmable processor-based subsystem, a spatial trackeroperatively connected to the programmable processor-based subsystem, atleast one mock welding tool capable of being spatially tracked by thespatial tracker, and at least one display device operatively connectedto the programmable processor-based subsystem. The system is capable ofsimulating, in virtual reality space, a weld puddle having real-timemolten metal fluidity and heat dissipation characteristics. The systemis further capable of displaying the simulated weld puddle on thedisplay device in real-time.

While the invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the invention without departing from its scope.Therefore, it is intended that the invention not be limited to theparticular embodiment disclosed, but that the invention will include allembodiments falling within the scope of the appended claims.

What is claimed is:
 1. A virtual reality welding system comprising: aprogrammable processor-based subsystem; a spatial tracker operativelyconnected to said programmable processor-based subsystem; at least onemock welding tool capable of being spatially tracked by said spatialtracker, said spatial tracker comprising a tactilely resistive tip tosimulate resistive feedback that occurs during welding thereby drivingfeedback for use in adjusting or maintaining welding procedure, saidmock welding tool emitting simulated particles onto a surface of atexture map; and at least one display device operatively connected tosaid programmable processor-based subsystem, said display deviceproviding visual cues during welding to provide immediate feedback bydisplaying overlaid colors or indicators for each tracked parameterbased upon predefined limits or tolerances for said tracked parameter,wherein said system simulates, in a virtual reality space, a weld puddlehaving real-time molten metal fluidity and heat dissipationcharacteristics, and displaying said simulated weld puddle on said atleast one display device in real-time, said virtual reality spacecomprising a welding element displacement map grid, in which said mapgrid defines surface resolution with changeable channel parameter valuesassigned to each portion of said grid, said values dynamically changingin real-time during a simulated welding process, said real-time moltenmetal fluidity and heat dissipation characteristics of said simulatedweld puddle provide real-time visual feedback to a user of said mockwelding tool when displayed on said at least one display device, said atleast one display device comprising a user-viewable face-mounted displaydevice, allowing said user to adjust or maintain a welding technique inreal-time in response to said real-time visual feedback, and whereinsaid real-time molten metal fluidity and heat dissipationcharacteristics of said simulated weld puddle are illustrated on saidtexture map comprising channels of information which comprise at least afirst channel which stores a displacement value for any liquefied metalat a wexel location; a second channel which stores a value giving amagnitude of heat at the wexel location; a third channel which stores adisplacement value for a solidified metal at the wexel location; and afourth channel which stores logical information about the wexel,including a representation regarding slag at the wexel location, andwherein when said particles make contact with the surface of the texturemap, said particles interact with each other and the texture map andbuild up in real-time, wherein more heat is added the nearer the wexelis to an emitter and heat is modeled in dependence on distance and anamount of time that heat is input from the emitter, and said weld puddleis rendered in virtual reality space for wexels having enough heat aswherever said heat exceeds a threshold value, the wexel at that wexellocation liquefies, causing the displacement value for said liquefiedmetal to raise up for those wexel locations, and wherein saiddisplacement is determined by sampling the highest particles at eachwexel location, and further wherein as the emitter moves on along theweld trajectory, the wexel locations left behind cool with heat removedfrom wexel locations at a defined rate, wherein when a cooling thresholdis reached, the wexel at that wexel location solidifies.
 2. The systemof claim 1 wherein said at least one display device includes at leastone user-viewable face-mounted display device capable of being spatiallytracked by said spatial tracker.
 3. The system of claim 1 wherein saidprogrammable processor-based subsystem includes at least one graphicprocessing unit (GPU).
 4. The system of claim 1 wherein said simulatedweld puddle comprises, in said virtual reality space, a plurality oftemporary virtual dynamic fluid particles overlaying a portion of avirtual surface displacement map.
 5. The system of claim 1 wherein saidprogrammable processor-based subsystem supports implementation of dataparallel algorithms.
 6. The system of claim 1 further comprising awelding user interface simulating a real-world welding power source userinterface in real time.
 7. The system of claim 3 wherein said real-timemolten metal fluidity and heat dissipation characteristics of saidsimulated weld puddle are generated by a physics model operating on saidat least one GPU.
 8. The system of claim 1 wherein said system simulatesin said virtual reality space, a weld bead having a real-time weld beadwake characteristic resulting from a real-timefluidity-to-solidification transition of said simulated weld puddle assaid simulated weld puddle is moved, and displaying said simulated weldbead on said at least one display device.
 9. The system of claim 1further comprising a welding coupon having at least one surface andsimulating a real-world part to be welded, wherein said at least onesurface of said welding coupon is simulated in said virtual realityspace as a double displacement layer including a solid displacementlayer and a puddle displacement layer, wherein said puddle displacementlayer is capable of modifying said solid displacement layer.
 10. Amethod of training using a virtual reality welding system, said methodcomprising: moving a first mock welding tool with respect to a weldingcoupon in accordance with a first welding technique, said first mockwelding tool emitting simulated particles onto a surface of a texturemap; tracking said first mock welding tool in three-dimensional spaceusing said virtual reality welding system, and wherein said step oftracking further comprises calculating a real-time molten metal fluidityand heat dissipation characteristics of a simulated weld puddle areillustrated on a texture map comprising channels of information whichcomprise at least a first channel which stores a displacement value forany liquefied metal at the wexel location; a second channel which storesa value giving the magnitude of heat at the wexel location; a thirdchannel which stores a displacement value for a solidified metal at thewexel location; and a fourth channel which stores logical informationabout the wexel, including a representation regarding slag at the wexellocation; viewing a display of said virtual reality welding systemshowing a real-time virtual reality simulation of said first mockwelding tool and said welding coupon in a virtual reality space as saidsimulated first mock welding tool deposits a first simulated weld beadmaterial onto at least one simulated surface of said simulated weldingcoupon by forming a simulated weld puddle in a vicinity of a simulatedarc emitting from said simulated first mock welding tool, said displayproviding visual cues during welding to provide immediate feedback bydisplaying overlaid colors or indicators for each tracked parameterbased upon predefined limits or tolerances for said tracked parameter;viewing, on said display, first real-time molten metal fluidity and heatdissipation characteristics of said first simulated weld puddle, saidsimulated weld puddle comprising a welding element displacement mapgrid, in which said map grid defines surface resolution with changeablechannel parameter values assigned to each portion of said grid, saidvalues dynamically changing in real-time during a simulated weldingprocess; using a tactilely resistive tip on said first mock welding toolto simulate resistive feedback that occurs during welding therebydriving feedback for use in adjusting or maintaining welding procedure;and modifying, in real-time, at least one aspect of said first weldingtechnique in response to viewing said first real-time molten metalfluidity and heat dissipation characteristics of said first simulatedweld puddle, and wherein when said particles make contact with thesurface of the texture map, said particles interact with each other andthe texture map and build up in real-time, wherein more heat is addedthe nearer a wexel is to the emitter and heat is modeled in dependenceon distance and the amount of time that heat is input from the emitter,and said weld puddle is rendered in virtual reality space for wexelshaving enough heat as wherever said heat exceeds a threshold value, thewexel map liquefies, causing the displacement value for said liquefiedmetal to raise up for those wexel locations, and wherein saiddisplacement is determined by sampling the highest particles at eachwexel location, and further wherein as the emitter moves on along a weldtrajectory, the wexel locations left behind cool with heat removed fromwexel locations at a defined rate, wherein when a cooling threshold isreached, the wexel map solidifies.
 11. The method of claim 10 furthercomprising: moving a second mock welding tool with respect to saidwelding coupon in accordance with a second welding technique; trackingsaid second mock welding tool in three-dimensional space using saidvirtual reality welding system; viewing said display of said virtualreality training system showing said real-time virtual realitysimulation of said second mock welding tool, said welding coupon, andsaid first simulated weld bead material in said virtual reality space assaid simulated second mock welding tool deposits a second simulated weldbead material merging with said first simulated weld bead material byforming a second simulated weld puddle in the vicinity of a simulatedarc emitting from said simulated second mock welding tool; viewing, onsaid display, second real-time molten metal fluidity and heatdissipation characteristics of said second simulated weld puddle; andmodifying, in real-time, at least one aspect of said second weldingtechnique in response to viewing said second real-time molten metalfluidity and heat dissipation characteristics of said second simulatedweld puddle.
 12. The method of claim 10 further comprising: moving saidfirst mock welding tool with respect to said mock welding coupon inaccordance with a second welding technique; continuing to track saidfirst mock welding tool in three-dimensional space using said virtualreality welding system; viewing said display of said virtual realitytraining system showing said real-time virtual reality simulation ofsaid first mock welding tool, said welding coupon, and said firstsimulated weld bead material in said virtual reality space as saidsimulated first mock welding tool deposits a second simulated weld beadmaterial merging with said first simulated weld bead material by forminga second simulated weld puddle in the vicinity of said simulated arcemitting from said simulated first mock welding tool; viewing, on saiddisplay, second real-time molten metal fluidity and heat dissipationcharacteristics of said second simulated weld puddle; and modifying, inreal-time, at least one aspect of said second welding technique inresponse to viewing said second real-time molten metal fluidity and heatdissipation characteristics of said second simulated weld puddle. 13.The method of claim 10 wherein said display is presented on auser-viewable face mounted display device.
 14. The method of claim 10wherein said display is presented on an observer display device.
 15. Awelding simulation comprising: means for creating a simulated real-timeweld puddle, said means emitting simulated particles onto a surface of atexture map; means for simulating a real-time molten metal fluiditycharacteristic of said simulated weld puddle; and means for simulating areal-time heat dissipation characteristic of said simulated weld puddle;means for displaying said simulated weld puddle with at least saidsimulated molten metal fluidity and heat dissipation characteristics ona user-viewable face-mounted display device; means for providing tactileresistive feedback that occurs during welding thereby driving feedbackfor use in adjusting or maintaining welding procedure; and means forproviding visual cues during welding to provide immediate feedback bydisplaying overlaid colors or indicators for each tracked parameterbased upon predefined limits or tolerances for said tracked parameter,and wherein said means for providing visual cues includes real-timemolten metal fluidity and heat dissipation characteristics of saidsimulated weld puddle which are illustrated on a texture map comprisingchannels of information which comprise at least a first channel whichstores a displacement value for any liquefied metal at the wexellocation; a second channel which stores a value giving the magnitude ofheat at the wexel location; a third channel which stores a displacementvalue for a solidified metal at the wexel location; and a fourth channelwhich stores logical information about the wexel, including arepresentation regarding slag at the wexel location, and wherein whensaid particles make contact with the surface of the texture map, saidparticles interact with each other and the texture map and build up inreal-time, wherein more heat is added the nearer a wexel is to theemitter and heat is modeled in dependence on distance and the amount oftime that heat is input from the emitter, and said weld puddle isrendered in virtual reality space for wexels having enough heat aswherever said heat exceeds a threshold value, the wexel map liquefies,causing the displacement value for said liquefied metal to raise up forthose wexel locations, and wherein said displacement is determined bysampling the highest particles at each wexel location, and furtherwherein as the emitter moves on along the weld trajectory, the wexellocations left behind cool with heat removed from wexel locations at adefined rate, wherein when a cooling threshold is reached, the wexel mapsolidifies.
 16. The welding simulation of claim 15 further comprisingmeans for simulating a real-time weld bead wake characteristic of asimulated weld in response to a welding technique of a user.
 17. Thewelding simulation of claim 15 further comprising means for simulatingan undercut state of a simulated weld caused by a welding technique of auser.
 18. The welding simulation of claim 15 further comprising meansfor simulating a porosity state of a simulated weld caused by a weldingtechnique of a user.
 19. The welding simulation of claim 15 furthercomprising means for simulating a burnthrough state of a simulated weldcaused by a welding technique of a user.
 20. A virtual reality weldingsystem comprising: a programmable processor-based subsystem; a spatialtracker operatively connected to said programmable processor-basedsubsystem; at least one mock welding tool emitting simulated particlesonto a surface of a welding element map and configured to be spatiallytracked by said spatial tracker; and at least one display deviceoperatively connected to said programmable processor-based subsystem;wherein said system is configured to simulate, in a virtual realityspace, a weld puddle having real-time molten metal fluidity and heatdissipation characteristics, and display said simulated weld puddle onsaid at least one display device in real-time; and wherein said weldpuddle is represented in the virtual reality space as a portion of saidwelding element map comprising a plurality of welding elements eachhaving changeable channel parameter values that dynamically change inreal time during a simulated welding process and represent at least amolten metal fluidity displacement and a solid metal displacement, basedupon a cooling threshold value for said transition between said moltenmetal to a solid metal.
 21. The system of claim 20 wherein said at leastone display device includes at least one user-viewable face-mounteddisplay device capable of being spatially tracked by said spatialtracker.
 22. The system of claim 20 wherein said simulated weld puddlecomprises, in said virtual reality space, a plurality of temporaryvirtual dynamic fluid particles overlaying a portion of a virtualsurface displacement map.
 23. The system of claim 20 further comprisinga welding user interface simulating a real-world welding power sourceuser interface in real time.
 24. The system of claim 23 wherein saidreal-time molten metal fluidity and heat dissipation characteristics ofsaid simulated weld puddle are generated by a physics model operating onat least one GPU.
 25. The system of claim 20 wherein said systemsimulates in said virtual reality space, a weld bead having a real-timeweld bead wake characteristic resulting from a real-timefluidity-to-solidification transition of said simulated weld puddle assaid simulated weld puddle is moved, and displaying said simulated weldbead on said at least one display device.
 26. The system of claim 20further comprising a welding coupon having at least one surface andsimulating a real-world part to be welded, wherein said at least onesurface of said welding coupon is simulated in said virtual realityspace as a double displacement layer including a solid displacementlayer and a puddle displacement layer, wherein said puddle displacementlayer is capable of modifying said solid displacement layer.
 27. Avirtual reality welding system comprising: a programmableprocessor-based subsystem; a spatial tracker operatively connected tosaid programmable processor-based subsystem; at least one mock weldingtool emitting simulated particles onto a surface and configured to bespatially tracked by said spatial tracker; and at least one displaydevice operatively connected to said programmable processor-basedsubsystem, wherein said system is configured to simulate, in a virtualreality space, a weld puddle created by those particles havingsufficient heat, and having real-time molten metal fluidity and heatdissipation characteristics, and display said simulated weld puddle onsaid at least one display device in real-time; and wherein said weldpuddle is represented in the virtual reality space as a puddledisplacement layer overlaid onto a solid displacement layer that ismodified in real time by the puddle displacement layer, based upon acooling threshold value for said transition between said molten metal tosaid solid metal.
 28. The system of claim 27 wherein said at least onedisplay device includes at least one user-viewable face-mounted displaydevice capable of being spatially tracked by said spatial tracker. 29.The system of claim 27 wherein said simulated weld puddle comprises, insaid virtual reality space, a plurality of temporary virtual dynamicfluid particles overlaying a portion of a virtual surface displacementmap.
 30. The system of claim 27 further comprising a welding userinterface simulating a real-world welding power source user interface inreal time.
 31. The system of claim 30 wherein said real-time moltenmetal fluidity and heat dissipation characteristics of said simulatedweld puddle are generated by a physics model operating on at least oneGPU.
 32. The system of claim 27 wherein said system simulates in saidvirtual reality space, a weld bead having a real-time weld bead wakecharacteristic resulting from a real-time fluidity-to-solidificationtransition of said simulated weld puddle as said simulated weld puddleis moved, and displaying said simulated weld bead on said at least onedisplay device.
 33. The system of claim 27 further comprising a weldingcoupon having at least one surface and simulating a real-world part tobe welded, wherein said at least one surface of said welding coupon issimulated in said virtual reality space as a double displacement layerincluding a solid displacement layer and a puddle displacement layer,wherein said puddle displacement layer is capable of modifying saidsolid displacement layer.
 34. A virtual reality welding systemcomprising: a programmable processor-based subsystem; a spatial trackeroperatively connected to said programmable processor-based subsystem; atleast one mock welding tool emitting simulated particles onto a surfaceand configured to be spatially tracked by said spatial tracker; and atleast one display device operatively connected to said programmableprocessor-based subsystem; and wherein said system is configured tosimulate, in a virtual reality space, a weld puddle created by thoseparticles having sufficient heat, and having real-time molten metalfluidity and heat dissipation characteristics, and display saidsimulated weld puddle on said at least one display device in real-time;and wherein said weld puddle is represented in the virtual reality spaceas a plurality of temporally temporary virtual dynamic fluid particlesinteracting with a portion of a welding element displacement map in realtime to maintain a processing load of said programmable processor-basedsubsystem to be substantially constant during a simulated weldingprocess.
 35. The system of claim 34 wherein said at least one displaydevice includes at least one user-viewable face-mounted display devicecapable of being spatially tracked by said spatial tracker.
 36. Thesystem of claim 34 wherein said simulated weld puddle comprises, in saidvirtual reality space, a plurality of temporary virtual dynamic fluidparticles overlaying a portion of a virtual surface displacement map.37. The system of claim 34 further comprising a welding user interfacesimulating a real-world welding power source user interface in realtime.
 38. The system of claim 37 wherein said real-time molten metalfluidity and heat dissipation characteristics of said simulated weldpuddle are generated by a physics model operating on at least one GPU.39. The system of claim 34 wherein said system simulates in said virtualreality space, a weld bead having a real-time weld bead wakecharacteristic resulting from a real-time fluidity-to-solidificationtransition of said simulated weld puddle as said simulated weld puddleis moved, and displaying said simulated weld bead on said at least onedisplay device.
 40. The system of claim 34 further comprising a weldingcoupon having at least one surface and simulating a real-world part tobe welded, wherein said at least one surface of said welding coupon issimulated in said virtual reality space as a double displacement layerincluding a solid displacement layer and a puddle displacement layer,wherein said puddle displacement layer is capable of modifying saidsolid displacement layer.
 41. A virtual reality welding systemcomprising: a programmable processor-based subsystem; a spatial trackeroperatively connected to said programmable processor-based subsystem; atleast one mock welding tool emitting simulated particles onto a surfaceand configured to be spatially tracked by said spatial tracker; and atleast one display device operatively connected to said programmableprocessor-based subsystem; and wherein said system is configured tosimulate, in a virtual reality space, a weld puddle having real-timemolten metal fluidity and heat dissipation characteristics, and displaysaid simulated weld puddle on said at least one display device inreal-time; and wherein said weld puddle is represented in the virtualreality space by a displacement map and a particle system in whichparticles in said particle system interact and collide with saiddisplacement map, each of said particles being virtual dynamic particlesand provide the liquid behavior of said weld puddle, and further whereina texture map is created in which each element of said map is a wexelcomprised of at least four channels of information which defines aweldable surface in said virtual reality space, each channel containingat least four floating point numbers in which said channels comprise: afirst channel which stores a displacement value for any liquefied metalat the wexel location; a second channel which stores a value giving themagnitude of heat at the wexel location; a third channel which stores adisplacement value for a solidified metal at the wexel location; and afourth channel which stores logical information about the wexel,including a representation regarding slag at the wexel location; andwhen said particles make contact with the surface of the texture map,said particles interact with each other and the texture map and build upin real-time, wherein more heat is added the nearer the wexel is to theemitter and heat is modeled in dependence on distance and the amount oftime that heat is input from the emitter, and said weld puddle isrendered in virtual reality space for wexels having enough heat aswherever said heat exceeds a threshold value, the wexel at that wexellocation liquefies, causing the displacement value for said liquefiedmetal to raise up for those wexel locations, and wherein saiddisplacement is determined by sampling the highest particles at eachwexel location, and further wherein as the emitter moves on along theweld trajectory, the wexel locations left behind cool with heat removedfrom wexel locations at a defined rate, wherein when a cooling thresholdis reached, the wexel at that wexel location solidifies.
 42. The systemof claim 41 wherein said particles stream from an emitter and make firstcontact with a surface of a simulated welding coupon where said surfaceis defined by said wexel map; and further wherein said particlesinteract with each other and said wexel map and build up in real-time;and further wherein more heat is added the nearer said wexel is to theemitter.
 43. The system of claim 42 wherein heat is modeled independence on a distance from an arc point and an amount of time thatsaid heat is input from said arc, and further wherein visuals are drivenby said heat wherein said weld puddle is rendered in virtual realityspace for wexels having a sufficient quantity of heat.
 44. The system ofclaim 43 wherein said wexel map liquefies when it reaches a heatingthreshold, thereby causing said first channel to increase for saidliquefied wexel map locations; and further wherein said wexel mapsolidifies when said liquefied wexel map locations go below a coolingthreshold and a value of said first channel is converted into a valuefor said third channel.